Research On Resource Reservation Technology Of Enterprise Video Conference Service Quality Assurance Systems

The video conferencing systems based on IP network do not have the advantages of low delay,low jitter and bandwidth guarantee provided by traditional telecommunication private network.This is mainly because IP network is designed based on connectionless packet switching and provides “best effort” service,so it is difficult to guarantee the quality of service(QoS)for the video conference.However,with the development of Internet and software technology,the video conferencing systems based on IP transmission network have the advantages of high usability and reasonable price(including the terminal price and network price).Based on these advantages,the video conferencing systems with 1080 P or higher resolution are rapidly popularized,and multi-party conferencing demand is strong.Especially since the outbreak of the epidemic in the first half of 2020,the video conferencing systems based on IP transmission network have become a rigid demand of many industries.However,the institutions such as government agencies,financial institutions and other institutions put forward higher requirements for the quality of video services than the ordinary consumers do.Because the Internet does not have the ability to provide QoS,this thesis studies the video conference service quality assurance and resource reservation algorithm in different conference scenarios in the enterprise network communication environment,and is committed to achieving the goal of video conference service quality assurance and improving network resource utilization.The specific research contents and related achievements are as follows:(1)This thesis studies the process of QoS assurance for enterprise video conferencing system,and proposes a SDN based enterprise video conference QoS assurance framework(EVCSQoS-SDN).From the perspective of system science,the internal process and connectivity of resource reservation and deployment are analyzed mathematically so that the architecture of resource reservation and deployment is formally defined,which provides a theoretical basis for the establishment of resource reservation and deployment system model based on SDN controller.(2)Based on the resource reservation and deployment architecture,a SDN controller based resource reservation and deployment system model is established to obtain the core mechanism of resource reservation and deployment,which supports the algorithm mechanism required by the resource reservation algorithm.(3)In large-scale conference request scenarios,reserving bandwidth for conferences in advance will lead to fine-grained changes of available bandwidth over time in the future,especially when there are many conference requests at the same time,the time cost will increase greatly.The classical time-domain resource management methods including the flexible timeslot-based resource management method and the dynamic timeslot-based resource management method have the problems of high computational complexity,poor scalability,and low resource utilization.To solve this problem,this thesis first proposes a new time management method: elastic timeslot method.Then,combining with the dynamic change of resources and elastic timeslot method,the elastic timeslot-based advance reservation algorithm(ETARA)is proposed.The experimental results show that ETARA can achieve the same acceptance ratio as the flexible timeslot-based resource management method,and the running time is 57 times lower than that of the latter;although the running time of ETARA is more than that of the dynamic timeslot-based resource management method,the acceptance ratio obtained by ETARA is twice that of the latter.(4)For the multi-party conferences,using multicast transmission can save bandwidth.In the real scene,participants can enter the video conference or leave midway.Advance reservation based on dynamic multicast supports the participants to enter and leave the conferencing flexibly.For the video conference charging according to the length of the conference,it is of great significance to require users to provide specific entry and departure time.On the one hand,if the conference members are charged according to the same conferencing duration,it will inevitably increase the additional cost of users;on the other hand,because the reserved resources are not used,the congestion rate of other conference requests is increased.In this thesis,we first construct the problem of maximizing the number of admitted Dynamic Multicast requests in the Advance Reservation environment(MDMAR)and prove that the problem is NP-complete.Then,the ILP mathematical model and heuristic algorithm are designed by considering the two mechanisms of fixed path and variable path and the heterogeneous characteristics of the bandwidth requirements of the receiver.Due to the high complexity and poor scalability of the ILP model,this thesis verifies the performance of the heuristic algorithm in a small network and large campus network respectively.Simulation results show that the heuristic algorithm based on simulated annealing can obtain the optimal solution like the ILP model,10% higher of the acceptance ratio than the greedy algorithm.The main work of this thesis is to study the system structure and resource reservation algorithm of enterprise video conference system under the controlled network resource environment,to realize the QoS guarantee of video conference system and improve the utilization rate of network resources.In the future work,we will further deepen the research of QoS system architecture and resource reservation algorithm to adapt to more complex video conferencing application scenarios and other application scenarios.